Furnace-front.



J. H. HUME.

FURNACE FRONT. APPLICATION FILED MAR. 25, 1913.

1,076,428. Patnted 0013. 21, 1913.

COLUMBIA PLANOURAPH cm. WASHINGTON, D. c.

JAMES HOWDEN HUME, 0F GLASGOIV, SCOTLAND.

FURNACE-FRONT.

Specification of Letters Patent.

Patented Oct. 21,1913.

Application filed March 25, 1913. Serial No. 756,709.

To all whom it may concern:

Be it known that I, JAMES IIownEN HUME, a subject of the King of theUnited Kingdom of Great Britain and Ireland, and residing at Glasgow,Scotland, have invented a certain new and useful Improvement inFurnace-Fronts, of which the following is a specification.

This invention relates to the fronts of furnaces particularly for forceddraft installations and has for its Jrimary object to provide improveddevices arranged to interlock the furnace door and the forced draft airsupply valves, so as to insure that the furnace door and the air supplyvalves shall not be open at the same time.

According to a preferred form of the invention, the door is hinged atits upper end so as to open inivardly on a substantially horizontal axisand is counterbalanced, while a lever for controlling the air supplyvalves is provided with an extension adapt ed to cooperate with a membersuitably guided on the furnace front and serving in one position of saidlever to lock the counterbalancing means and thereby the door: the faceof the door is provided with packing so fitted relatively to the framingat the furnace opening that an air-tight joint will always be insuredwhen the furnace door is closed and the air supply valves are open:other features will appear from the following description and appendedclaims.

In the accompanying drawings Figure 1 is a front elevation and Fig. 2 isa side elevation of a furnace front embodying the invention: Fig. 3 is avertical section at right angles to Fig. 1: Fig. 4: is a detail viewshowing the forced draft air supply valves and relative connections.

eferring to the drawings, the upper end of the furnace door A, which isinclined, is hinged at B so that the door opens inwardly on asubstantially horizontal axis preferably parallel with the plane of thefurnace front C, the hinge being carried by an outwardly projectingshelf D on a renewable framing I) at the furnace opening. To the upperend of the door are connected by means of arms E balance weights F, Fand mounted in guides G secured to the furnace front is a verticallymovable member I-I terminating at its upper end in an outwardly andupwardly curved extension I; While formed on, or fitted to, a lever Jfor actuating the air supply valves K secured to a shaft L operated bymeans of sector gear wheels M, N is a horndike extension 0 formed with acam shaped edge P in constant engagement with the lower end of themember H, which extension O, when the door A is closed and the valves Kare open, causes the member H to be moved upwardly, whereby the upperextremity of the extension I engages the balance weight I to lock it andthereby also lock the door which is maintained against its seat. Thevalves K aforesaid are adapted to be rotated by means of the sector gearM, which gear is rotatable with the lever J and is in engagement withthe sector gear N secured to the shaft L.

The furnace door A is faced with differently inclined strips of packingP, Q at its upper and lower marginal edges, the packing at the upperedge being adapted to engage with a flange It extending inwardly fromthe shelf D and tansversoly of the furnace opening, and the packing atthe lower edge of the door, which edge is sloped away from the outerface of the door, being adapted to engage an inclined wearing face S atthe inner lower edge of the base of the renewable framing 1 resting onthe front of the base plate T at the furnace opening adjacent theopening I, thus insuring an air-tight joint when the door is closed.

When the lever J is operated to close the valves K, the extension I ofthe vertically movable member H is disengaged from the balance weight F,as indicated in Figs. 1 and 2, so that the door A may be readily trippedup beyond the dead center position, whereupon, by the action of thebalance weights F, F, the door will be raised clear of the door opening,as indicated by dotted lines in Fig. 3.

lVhat I claim is 1. In a furnace front, in combination, a furnace doorhinged on a horizontal axis, a lever provided with an extension adaptedto be moved toward and from the door, air supply valves, connect-ionsbetween said valves and said lever for imparting closing movement to thevalves on movement of said lever in one direction, a balance weighttending to open the door and means operable by said lever serving in oneposition of the lever to lock the balance weight and thereby also lockthe door.

2. In a furnace front, in combination, a furnace door hinged on ahorizontal axis to open inwardly toward the furnace, a lever providedwith an extension adapted to be moved toward and from the door, airsupply valves, connections between said valves and said lever forimparting closing movement to the valves on movement of said lever inone direction, a balance weight tending to open the door and meansoperable by said lever serving in one position of the lever to lock thebalance weight and, thereby also lock the door.

3. In a furnace front, a furnace door hinged on a horizontal axis toopen inwardly toward the furnace, a renewable framing including a basepiece and a shelf on which the door is carried, said shelf having aflange, valves for controlling the supply of air to said furnace, alever controlling said valves, said lever when in position to open thevalves acting to prevent the opening of door adapted to engage saidflange and said base piece.

4:. In a furnace front, a furnace door hinged on a horizontal axis toopen inwardly toward the furnace, a shelf on which the door is carried,said shelf having a flange, valves for controlling the supply of air tosaid furnace, a lever controlling said valves, said valves being closedwhen the door is open, a base plate, means associated with said baseplate affording a wearing face, and differently inclined packing stripson the outer face of the door adapted to engage said flange and saidwearing face.

5. In a furnace front, a furnace door hinged on a horizontal axis toopen inwardly toward the furnace, a base plate, a renewable framingincluding a base piece resting on said base plate and a shelf on whichthe door is carried, said shelf having a flange, valves for controllingthe supply of air to said furnace, and a lever controlling said valves,said lever when in position to open the valves acting to prevent theopening of the door.

(3. In a furnace front, in combination a furnace door hinged on ahorizontal axis, air supply valves, a valve-actuating lever, a balanceweight tending to open'the door and means operable by said lever servingin one position of the lever to lock the balance weight and thereby alsolock the door.

7. In a fuinace front, in combination, a furnace door hinged on ahorizontal axis, air supply valves, a valve-actuating lever, a balanceweight tending to open the door and a vertically movable catch deviceoperable by said lever, said catch device serving in one position of thelever to lock the balance weight and thereby also look the door.

8. In a furnace front, in combination, a furnace door hinged on ahorizontal axis, air supply valves, a valve-actuating member, saidmember formed with a cam surface, a balance weight tending to open thedoor, and a catch device engaged by said cam surface, said catch deviceserving in one position of said member to lock the balance weight andthereby also lock the door.

9. In a. furnace front,,in combination, a balanced furnace door hingedon a horizontal axis, air supply valves, a valve-actuating member, saidmember formed with a cam surface, and a vertically movable catch deviceengaged by said cam surface, said catch device servingin one position ofsaid member to lock the door in closed position.

in testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

JAMES HOlVDEN HUMIL Witnesses JOHN MOCLEA Y, Tnoiuas Bisiior GRAHAM.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, I). C.

